[Detection of co-infection with Lyme spirochetes and Spotted fever group rickettsiae in a group of Haemaphysalis longicornis].

OBJECTIVE: The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis (anaplasmosisin) in wild animals and ticks in the mountain areas of Zhejiang province.

METHODS: Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia(anaplasma) from samples of mice and ticks.

RESULTS: 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borrelia burgdorferi and two 5' fragments of Ehrlichia (anaplasma) 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borrelia burgdorferi and eight 5' fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and Spotted fever group rickettsiae. The positive sequences of 5S-23S rDNA intergenic spacer and ompA gene were tested and analyzed as Lyme spirochetes while rickettsia which was closely related to Borrelia valaisiana and R. massiliae.

CONCLUSION: This was the first report about co-infection of Lyme spirochetes and Spotted fever group rickettsiae found in the same group of adult Haemaphysalis longicornis. It is very important to strengthen the surveillance program on tick-borne infectious disease and their pathogenic in vectors, wild animals and targeted high risk groups and to differentiate the clinical manifestation and diagnosis to extend the knowledge of tick-borne infectious diseases in Zhejiang.